Lightweight brake rotor and components with composite materials

ABSTRACT

One embodiment of the invention includes a method comprising: placing a first insert and a second insert in a casting mold and wherein the first insert and second insert comprising a plurality of connecting post extending inbetween so that the first insert and second insert are in spaced-apart relationship in the mold, each of the first insert and the second insert comprising a first material; casting a molten second material into the casting mold so that the second material flows between the first insert and the second insert and solidifying the second material to provide a product comprising a cast over body portion with the first insert and second insert and so that the second material is mechanically locked or metallurgically bonded to the first material and so that one or both of the first insert and the second insert provides working surface for the product.

TECHNICAL FIELD

The field to which the disclosure generally relates includes methods ofjoining different materials and products made therefrom.

BACKGROUND

Vehicles that include wheels such as, but not limited to, automobiles,trucks, buses, airplanes and the like typically include braking systems.Such braking systems commonly include drum or disc brake rotors.

SUMMARY OF EXEMPLARY EMBODIMENTS

One embodiment of the invention includes a method comprising: placing afirst insert and a second insert in a casting mold and wherein the firstinsert and second insert comprising a plurality of connecting postextending inbetween so that the first insert and second insert are inspaced-apart relationship in the mold, each of the first insert and thesecond insert comprising a first material; casting a molten secondmaterial into the casting mold so that the second material flows betweenthe first insert and the second insert and solidifying the secondmaterial to provide a product comprising a cast over body portion withthe first insert and second insert and so that the second material ismechanically locked or metallurgically bonded to the first material andso that one or both of the first insert and the second insert providesworking surface for the product.

Other exemplary embodiments of the invention will become apparent fromthe detailed description provided hereinafter. It should be understoodthat the detailed description and specific examples, while disclosingexemplary embodiments of the invention, are intended for purposes ofillustration only and are not intended to limit the scope of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the invention will become more fully understoodfrom the detailed description and the accompanying drawings, wherein:

FIG. 1 illustrates a braking wheel useful in a method according to oneembodiment of the invention.

FIG. 2 illustrates a vented disc brake rotor including a braking wheeland a cast over body portion including a hub according to one embodimentof the invention.

FIG. 3 illustrates an insert with projections having a trapezoidal shapeuseful in making an brake rotor according to one embodiment of theinvention.

FIG. 4 illustrates a non-vented disc brake rotor including a brakingwheel and a cast over body portion including a hub according to oneembodiment of the invention.

FIG. 5 illustrates a braking wheel for a drum rotor useful in a methodaccording to one embodiment of the invention.

FIG. 6 illustrates a drum rotor including a braking wheel and cast overbody portion including a hub according to one embodiment of theinvention.

FIG. 7 illustrates a sectioned core insert useful in making a disc brakerotor according to one embodiment of the invention.

FIG. 8 illustrates a sectional plan view of a sectioned casting coreoverlying a portion of a braking wheel including an annular disc andpost extending therefrom and wherein the post received in slots formedin the casting core according to one embodiment of the invention.

FIG. 9 illustrates a method of making a disc brake rotor according toone embodiment of the invention.

FIG. 10 illustrates placing a first annular disc insert in a castingmold in a method of making a brake rotor according to one embodiment ofthe invention.

FIG. 11 illustrates a casting core including a plurality of channelsformed therein for use in a method according to one embodiment of theinvention.

FIG. 12 illustrates a method of placing the casting core of FIG. 10 in acasting mold according to one embodiment of the invention.

FIG. 13 illustrates an annular disc insert including locating featuresuseful in a method according to one embodiment of the invention.

FIG. 14 illustrates a method of closing the casting mold and pouringmolten material into the mold according to one embodiment of theinvention.

FIG. 15 illustrates a vertical casting method including placing thefirst and second annular disc insert with locating feature in first andsecond mold halves respectively, and pouring molten material into thecasting mold according to one embodiment of the invention.

FIG. 16 is a sectional, side view of an annular disc insert including aplurality of projections which may have a trapezoid-shape, L-shape orT-shape that is useful according to one embodiment of the invention.

FIG. 17A is a perspective view with portions broken away of a brakerotor with straight vanes according to one embodiment of the invention.

FIG. 17B is a perspective view with portions broken away of a brakerotor with pillar-type vanes according to another embodiment of theinvention.

FIG. 17C is a perspective view with portions broken away of a brakerotor with straight, tangential vanes according to another embodiment ofthe invention.

FIG. 17D is a perspective view with portions broken away of a brakerotor with curved, tangential vanes according to another embodiment ofthe invention.

FIG. 18 is a sectional, side view of an annular insert includingdownwardly extending legs stamped out of the insert and useful in amethod according to one embodiment of the invention.

FIG. 19 illustrates a sectional, side view of an annular insertincluding a tab stamped out of the insert including a downwardlyextending leg portion and a foot useful in one embodiment of theinvention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The following description of the embodiment(s) is merely exemplary innature and is in no way intended to limit the invention, itsapplication, or uses.

Referring now to FIG. 1, one embodiment of the invention includesproviding a braking wheel 10 which may include a first insert 12 and asecond insert 14 which are maintained in spaced-apart relationship toeach other by a plurality of post 16 extending between the first insert12 and the second insert 14. In one embodiment, the first insert 12, thesecond insert 14 and the post 16 extending therebetween are cast from asingle first material and are a continuous casting. The braking wheel 10may be manufactured by casting, welding or other similar methods.

The braking wheel 10 may be utilized to make a disc brake rotor 18 shownin FIG. 2. The disc brake rotor 18 includes a cast over body 20including a hub portion 22 and a second portion 24 extending between thefirst insert 12 and the second insert 14. The second portion 24 of thecast over body 20 may cover the insert annular inner surface and theouter circumferential surfaces of the inserts 12, 14. A plurality ofvanes 26 or fins extending between the first insert 12 and the secondinsert 14 may define a plurality of vents 28 or channels therebetween toprovide a vented brake rotor as shown in FIG. 2. The vanes 26 may bestraight-shaped vanes, curved vanes, pillar-type vanes or any other typevane known to those skilled in the art. In one embodiment, each of thepost 16 of the brake wheel 10 may be surrounded by an associated vane 26so that the cast over body 20 is mechanically locked to the brake wheel10 or metallurgically bonded thereto at the post 16.

The braking wheel 10 may be made from a first material, such as castiron to provide a first braking surface 34 on an outer face of the firstinsert 12 and a second braking surface 36 on an outer surface of thesecond insert 14. The cast over body 20 may be made of a second materialthat has a density and melting point less than that of the firstmaterial. In one embodiment of the invention the second material mayinclude aluminum or alloy thereof. In one embodiment, all the exposedsurfaces of the rotor comprise the second material except the twoannular braking surfaces 34, 36 which comprise the first material. Thisarrangement prevents corrosion of the first material except at theexposed braking surfaces 34, 36. However, any corrosion at the exposedbraking surfaces 34, 36 may be removed by the brake pads rubbing againstthe braking surfaces 34, 36.

Referring again to FIG. 1, in one embodiment, the post 16 and/or aninner surface 30 of the first insert 12 and/or an inner surface 32 ofthe second insert 14 may be treated, for example by applying a coatingof graphite so that the inner surfaces 30, 32 and/or the post 16 is wetby the molten second material and a metallurgical bond is formed betweenthe cast over body portion and the inserts 12,14 or post 16.

Referring now to FIG. 3, in one embodiment the first insert 12 (or thesecond insert 14) includes a plurality of trapezoid-shaped projection16′ extending from an inner surface 30 of the first insert 12 (or aninner surface 32 of the second insert 14) thereof and wherein the secondmaterial is mechanically locked to the first material at the projectionsduring a casting process. At least one of the outer surface 34 of thefirst insert 12 (or the outer surface 36 of the second insert 14)provides a first braking surface. Still other embodiment of annular discinserts with projections 16′ are illustrates in FIGS. 16,18 and 19.

Referring now to FIG. 4, alternatively, the second portion 24 of thecast over body 20 may completely fill the space between the first insert12 and the second insert 14 to provide a solid non-vented disc brakerotor 18.

Referring now to FIG. 5, in another embodiment of the invention, thebrake wheel 10 may be constructed and arranged to form a cylindricalinner wall 14 with projections 16′ extending from an outer surface 36.In one embodiment the projection 16′ may have a trapezoid-shape,T-shape, L-shape, rectangular-shape and the like. Some examples of thedesigns for the projections 16′ are shown in FIG. 16. An inner face 32of the cylindrical wall provides a braking surface.

Referring now to FIG. 6, the brake wheel 10 of FIG. 5 may be utilized toprovide a cast over body 20 defining a hub portion 22 and a secondportion 24 to completely cover all the projections 16′ on the brakingwheel 10 to provide a drum brake rotor 18.

Referring now to FIG. 7, a casting core 42 may be utilized to make avented disc brake rotor shown in FIG. 2. The casting core 42 may be apermanent metal core. In one embodiment the core 42 may be sectionedinto many pieces each of which may be slid between the first insert 12and second insert 14 from a position associated with the outer diameterof the brake wheel 10 towards the center thereof. Each portion 44 of thecore 42 may include at least one slot 46 formed therein having an openend 48 to receive the post 16 extending between the first insert 12 andthe second insert 14.

FIG. 8 is a sectional, planer view of a braking wheel 10 including afirst insert 12 and a plurality of post 16 extending upwardly therefromand portions 44 of a core 42 overlying the first insert 12. During thecasting operations, the slots 46 formed in each portion 44 of the core42 will be filled with the second material to form vanes 26 extendingbetween the first insert 12 and the second insert 14. The vane 26 maycapture the post 16 or projections 16′ and be mechanically lockedthereto or the posts or projections may be treated so that the secondmaterial used to form the vane 26 is metallurgically bonded to the post16 or projection 16′. The core 42 may then be removed to leave vents 28or channels between vanes 26.

Referring now to FIG. 9, one embodiment of the invention includesplacing a braking wheel 10 and including a core 42 into at least one ofa first portion 50 of a casting mold 49 or second portion 52 of acasting mold wherein the second portion 52 includes a projection 54constructed and arranged to extend into the first portion 50 of acasting mold 49 to define the hub 22 of the brake rotor. The castingmold 49 may be a permanent metal mold. The material utilized for thebraking wheel may be a first material such as cast iron and a secondmolten material 56 may be poured into the casting mold through a chargeline 58. The second molten material 56 may be of a second material suchas aluminum which has a lower melting point and is lighter than thefirst material. The casting mold 49 may include a vent 60 and otherfeatures known to those skilled in the art.

FIGS. 10-14 illustrate another embodiment of making a brake rotor. Thefirst insert 12 may be a separate annular disc 12 with trapezoidalprojections 16′ as shown in FIG. 16 and placed in the first portion of acasting mold 50. Thereafter, a casting core 42 may be placed over thefirst insert 12 (as shown in FIG. 12). The core 42 as shown in FIG. 11may be a single intact piece including a plurality of channels 46 formedtherein and constructed and arranged to produce vanes 26 during thecasting process. FIG. 13 illustrates one embodiment of the invention inwhich the first insert 12 or the second insert 14 may include an annulardisc portion 59 with locating features 106 on the braking surfaces 34,36. As shown in FIG. 14, in one embodiment each of the first portion 50and second portion 52 of the casting mold 49 may include the locatingfeatures 64 working together with the locating features 106 on theinserts to hold the inserts in place in the mold for casting. Forexample a plurality of recesses 64 formed therein to receive thelocating features 106 so that each of the first insert 12 and secondinsert 14 may be held in a designed position. In another embodiment thesecond portion 52 of the casting mold 49 may include a magnet 104 tohold the second insert 14 and then be placed over the first portion 50to close the mold 49, and the molten second material 56 may then bepoured in through a charge line 58 to form a brake rotor having a castover body 20 including a hub 22 and a second portion 24 (not shown)extending between the first insert 12 and the second insert 14. Thelocating features 106 on the first insert 12 and the second insert 14may be machined off later. The locating features 106 may also beconstructed to rest on the shoulder of a specially designed mold and maybe clamped onto by the mold halves. To make a non-vented disc brakerotor the core 42 is not used.

Referring now to FIG. 15, in another embodiment each of the first insert12 and second insert 14 may be held in a vertical position. Moltenmaterial 56 may be poured into the casting mold 49 to provide a rotorincluding a cast over body portion 20 including a hub portion 22 and asecond portion 24 extending between the first insert 12 and the secondinsert 14, for example as shown in FIG. 4.

FIG. 16 illustrates one embodiment of a first insert 12 (or secondinsert 14) including a plurality of projection 16′ extending outwardlyfrom a inner surface 30 of the first insert 12. The first insert 12 mayinclude an outer first braking surface 34. The projections 16′ may beconstructed and arranged so that a mechanical lock is provided when thesecond material is cast into the casting mold. The projections 16′ mayhave any of a variety of shapes. For example, the projection 16′ may betrapezoid-shaped, L-shaped, T-shaped or may have any shape providing ashoulder or surface against which the second material may be trapped andthereby preventing the first insert 12 (or second insert 14) from beingpulled away from the second portion 24 of the cast over body 20.

FIG. 17A is a perspective view with portions broken away of a brakerotor according to one embodiment of the invention which includesstraight vanes 26 with individual post 16 trapped therein. FIG. 17B is aperspective view with portions broken away of a brake rotor according toanother embodiment of the invention of a pillar-type design. FIG. 17C isa perspective view with portions broken away of a brake rotor accordingto another embodiment of the invention including tangential, straightaluminum vanes 26 with vane-shaped cast iron post 16 trapped inside thealuminum vanes 26. FIG. 17D is a perspective view with portions brokenaway of a brake rotor according to another embodiment of the inventionincluding tangential, curved aluminum vanes 26 with individual cast ironpost 16 trapped inside the vanes 26.

FIG. 18 illustrates another embodiment of the invention including aninsert 14 which includes a plurality of projections 16′ which may beformed by stamping a downwardly extending leg portion 68 out of theinsert such as stainless steel or other material suitable for stamping.

As shown in FIG. 19, the projection 16′ may include a first bend 70 andsecond bend 72 therein to define a leg portion 68 and a foot portion 72which may be substantially parallel to the main body portion 76 of theinsert 14. In one embodiment, the projection 16′ may be stamped out ofthe main body portion 76 of the insert 14 at a location that is not inuse.

Various embodiments of the invention may include any design features asthat in traditional brake rotor designs, e.g., cross drilled holes orother machined features on the rotor surface, as well as coatings orheat treatment of rotor surfaces and the like. Various surfacetreatments may be performed on the first insert 12, second insert 14 andprojections 16′ or post 16 to improve the brake and/or rotorperformance.

According to various illustrative embodiments of the invention,frictional damping may be achieved by the movement of the interfacingsurfaces of the first material and the second material against eachother.

One embodiment of the invention includes a product which may have africtional damping means. In embodiments wherein at least a portion ofat least one of inner faces 30, 32 of the inserts 12, 14 respectively,or the post 16 may be coated with a material to product frictionaldamping. The coating may include fibers or particles that resist flowingwhen exposed to the temperature of a molten material such as in casting.

The above description of embodiments of the invention is merelyexemplary in nature and, thus, variations thereof are not to be regardedas a departure from the spirit and scope of the invention.

1. A method comprising: placing a first insert and a second insert in acasting mold so that the first insert and second insert are inspaced-apart relationship in the mold, each of the first insert and thesecond insert comprising a first material; casting a molten secondmaterial into the casting mold so that the second material flows betweenthe first insert and the second insert and solidifying the secondmaterial to provide a product comprising a cast over body portion withthe first insert and second insert, the cast over body portioncomprising the second material and so that the second material ismechanically locked or metallurgically bonded to the first material andso that one or both of the first insert and the second insert providesworking surface(s) for the product.
 2. A method as set forth in claim 1further comprising a plurality of post extending between and permanentlyconnecting the first insert and the second insert and wherein the secondmaterial surrounds each post and wherein the second material ismechanically locked to the first material at the posts, and wherein thepost extending between and connecting the inserts may be in the shape ofround rods, rectangular bars, or curved fins, and wherein the firstinsert and the second insert and the plurality of post are a singlecontinuous workpiece.
 3. A method as set forth in claim 1 wherein eachof the first insert and the second insert includes a plurality ofprojection extending from an inner face thereof, and wherein the secondmaterial is mechanically locked to the first material at theprojections, and wherein the projection is trapezoid-shaped, T-shaped,L-shaped, or rectangular-shaped, and wherein the first insert or secondinsert and the projections are a single continuous workpiece.
 4. Amethod as set forth in claim 1 wherein the second material has a lowermelting point, and a lower density if so designed, than that of thefirst material and wherein the examples of the first material are castiron, steel, and ceramic composite and the examples of the secondmaterial are aluminum alloy and cast steel.
 5. A method as set forth inclaim 1 wherein the first insert comprises a first annular brake discand wherein the second insert comprises a second annular brake disc andwherein the second material comprises a hub and a cast over body portionextending between the first insert and the second insert and wherein thebrake rotor is a disc brake rotor and wherein the first braking surfaceis provided by an outer surface of the first insert, and furthercomprising a second braking surface provided by an outer surface of thesecond insert, and wherein the brake rotor is either solid or vented. 6.A method as set forth in claim 2 further comprising providing asectioned annular casting core comprising a plurality of core sections,the core having slots formed therein each with an opened end, placingthe core sections between the first insert and the second insert priorto casting, and wherein an associated post is received in the slotthrough the open end, and after the solidifying, removing the core toprovide vanes extending between the first insert and the second insertwhere the slots in the casting core were and to provide vent channelsbetween the vanes, and wherein a permanent mold and permanent core maybe used to cast the second material.
 7. A method comprising: placing atleast a first insert in a casting mold so that the first insert, thefirst insert comprising a plurality of projections extending from firstsurface thereof and the first insert comprising a second surface, thesecond surface providing a working surface, the first insert comprisinga first material; casting a molten second material into the casting moldso that the second material provides a cast over body portion comprisingthe second material and so that the second material is mechanicallylocked to the plurality of projections and solidifying the secondmaterial to provide a product.
 8. A method as set forth in claim 7wherein the product is a drum brake rotor and wherein the first insertcomprises a cylindrical wall with projections extending from an outersurface of the cylinder wall and wherein the brake surface is providedby an inner wall of the cylindrical wall.
 9. A method as set forth inclaim 7 further comprising treating the inner surface of the firstinsert comprising applying a coating of graphite so that the innersurfaces are wet by a molten second material and a metallurgical bond isformed between the two materials.
 10. A method as set forth in claim 7further comprising providing a coating on inner surface of the firstinsert to provide frictional damping, and the coating comprising fibersor particles that resist flowing when exposed to the temperature of amolten second material.
 11. A method as set forth in claim 7 furthercomprising providing locating features on the working surface of thefirst insert wherein placing the first insert, in a casting moldcomprises holding the insert in place in the mold during the castingusing the locating features.
 12. A product comprising: placing a firstinsert and a second insert in a casting mold so that the first insertand second insert are in spaced-apart relationship in the mold, each ofthe first insert and the second insert comprising a first material;casting a molten second material into the casting mold so that thesecond material flows between the first insert and the second insert andsolidifying the second material to provide a product comprising a castover body portion with the first insert and second insert, the cast overbody portion comprising the second material and so that the secondmaterial is mechanically locked or metallurgically bonded to the firstmaterial and so that one or both of the first insert and the secondinsert provides working surface(s) for the product.
 13. A product as setforth in claim 12 further comprising a plurality of post extendingbetween and permanently connecting the first insert and the secondinsert and wherein the second material surrounds each post and whereinthe second material is mechanically locked to the first material at theposts, and wherein the post inbetween and connecting the inserts may bein the shape of round rods, rectangular bars, or curved fins and whereinthe first insert and the second insert and the plurality of post are asingle continuous workpiece.
 14. A product as set forth in claim 12wherein each of the first insert and the second insert includes aplurality of projections extending from an inner face thereof, andwherein the second material is mechanically locked to the first materialat the projections, and wherein at least one of the projections istrapezoid-shaped, T-shaped, L-shaped, or rectangular-shaped, and whereinthe first insert or second insert and the projections are a singlecontinuous workpiece.
 15. A product as set forth in claim 12 wherein thefirst insert comprises a first annular brake disc and wherein the secondinsert comprises a second annular brake disc and wherein the brake rotoris a disc brake rotor and wherein the first braking surface is providedby an outer surface of the first insert, and further comprising a secondbraking surface provided by an outer surface of the second insert, andwherein the brake rotor is either solid or vented.
 16. A productcomprising: placing at least a first insert in a casting mold so thatthe first insert, the first insert comprising a plurality of projectionsextending from first surface thereof and the first insert comprising asecond surface, the second surface providing a working surface, thefirst insert comprising a first material; casting a molten secondmaterial into the casting mold so that the second material provides acast over body portion comprising the second material and so that thesecond material is mechanically locked to the plurality of projectionsand solidifying the second material to provide a product.
 17. A productas set forth in claim 16 wherein the product is a drum brake rotorwherein the first insert comprises a cylindrical inner wall comprisingan inner surface and an outer surface and wherein the projection extendfrom the outer surface of the cylinder wall and wherein the brakingsurface is provided by the inner surface of the cylinder wall.
 18. Aproduct as set forth in claim 16 further comprising providing a coatingon an inner surface of the first insert to provide frictional damping,the coating comprising fibers or particles that resist flowing whenexposed to the temperature of a molten second material.